1. Field of the Invention
The present invention relates generally to disbursement systems for bulk material storage receptacles for fertilizers and the like. More particularly, the present invention relates to an improved disbursement system with dual doors and an intermediate auger for a tender trailer wherein the bulk material may be selectively dispensed via gravitational discharge or remotely via an intermediate auger system. Known related prior art may be found in U.S. class 222, subclass 561, class 241, subclass 73 and class 298, subclasses 24 and 27 and others.
2. Description of Prior Art
Known bulk material storage receptacle utilize various devices for unloading their cargo. These unloading devices are generally either a conveyor system for remotely transporting and subsequently disbursing the cargo or a gravity dump system. The former typically comprises a series of auger transporters for moving the cargo to the receptacle periphery while the latter typically comprises a gravitationally fed door for dumping the cargo onto the ground immediately below the receptacle.
Auger systems generally pivot between a transport or stowed position and a delivery or discharge position. During transport, a portion of the auger is generally positioned alongside the longitudinal axis of the tender while that portion pivots to another position (i.e., transverse to the tender) for unloading the tender during material discharge.
Gravitational systems are often preferred by operators for several reasons. For example, they are typically much quicker to unload than augering systems because of their larger throughput capacities. Also, auger systems usually require more maintenance and/or care during use. However, gravitational systems have limitations. For example, they only unload beneath the trailer. Also, because they depend on the force of gravity to disburse their cargo, they may become plugged and/or bridge, causing the cargo to become lodged in the trailer.
While the present invention may be utilized with fixed or permanent storage receptacles, it is particularly well suited for use with mobile bulk material tenders. Bulk material tenders of the type contemplated for use with the invention generally deliver large amounts of particulate material, usually in the range of 10 to 40 tons in a single load. This material is typically discharged by the auger system at rates approaching 4,000 lbs/min. When the gravity doors are used, the discharge rate is on the order of a couple of minutes. Even though large loads are the norm, the auger system usually unloads the tender quicker than the operator can properly position the auger system for discharge.
As will be appreciated by those skilled in the art, it is critical to efficiently and effectively position the discharge auger tubes for unloading, while providing suitable communication for the material between the tender and the discharge auger. The known prior art have utilized articulating or multi-sectioned auger tubes that are disassembled for stowing and must be reassembled for discharge. Reassembling or disassembling augers is time consuming and labor intensive, especially given the time requirements for unloading the tender with the auger system. Other types of prior art devices provide auger systems that are otherwise unduly complex, many having multiple sections that pivot or otherwise move in multiple axes. These complicated auger systems do not normally improve the overall quality of the material delivery but rather add to the costs for such delivery.
Several examples of overly complex devices are shown in the prior art, including U.S. Pat. Nos. 2,877,914, 3,326,397, and 4,613,275, all of which are of general relevance. Other complex, though interesting, devices are shown in U.S. Pat. Nos. 3,642,155 and 3,770,101, both to Carson. The Carson devices both appear to comprise an articulated unloading boom hinged to one end of a transport body for movement between a travel position and an unloading position. In the travel position, the boom is unfolded against one side of the body while the hinged boom sections are aligned in the unloading position. The boom comprises an upper section and a lower section pivotally joined by a hinge. A hydraulic actuator rotates the upper section between its travel position and its aligned unloading position relative to the lower section.
Another interesting device is shown in U.S. Pat. No. 4,093,087 to DeCoene. That patent shows a system for moving an unloading auger tube having a main segment and an end segment between the transport position and a selected unloading position. The end segment is angled with respect to the main segment and it is pivotally mounted on a lower inclined portion of a side wall so as to extend away from the central, vertical fore aft plane of the vehicle. The auger segments are disposed at predetermined angles to facilitate auger pivoting about a single axis located perpendicular to the inclined mounting surface of the side wall for movement between the stowed discharge positions.
Another overly complex device is shown U.S. Pat. No. 4,613,275 to Karlowski. The Karlowski patent shows an articulated support arrangement for attaching an auger system to a side wall of a truck. This arrangement permits the auger to move between a storage position against the side wall to an operating position parallel to the truck rear. The auger conveyor is supported by a swingable material conveyor support. The support includes a pivot arm moving arcuately about a hinge with a terminal clamp intermediately securing the arm to the auger conveyor. The clamp pivots about a second hinge and third hinge to enable the auger conveyor to pivot about multiple axes when moving between its storage and operating positions. Other patents showing complex devices of generally lesser relevance include U.S. Pat. Nos. 3,322,257 3,391,778, 3,638,816, 4,218,169, 4,419,037, 5,520,495 and 5,615,990.
While the above mentioned prior art devices are generally too complicated for efficient practical use, several simplistic devices are also known in the art. These devices typically require little time for conversion between the transport position and the delivery position. For example, U.S. Pat. No. 4,742,938 to Niewold shows a positioned mechanism for an auger in which the auger is hydraulically swung between its transport and working positions. The auger tube is mounted at its lower end by a swivel to a wall of a hopper, permitting the auger tube to swing into place via a hydraulic cylinder.
Similarly, U.S. Pat. Nos. 4,427,105, 5,108,249, 5,538,388 and 5,655,872 all show devices that pivot between a transport and working position via a hydraulic cylinder and a terminally hinged auger tube. However, all of these devices pivot about a terminal hinge. In other words, the hinge is located at the end of the tube.
A very interesting device is shown in U.S. Pat. No. 5,468,113 to Davis. Davis shows an auger that pivots in multiple axes about an intermediary point proximate one end. Apparently, the auger moves between the transport and delivery positions by pivoting about a first pivotal mount that cooperates with a second pivotal mount. When in the delivery position, the auger maintains dust-free communication with the storage receptacle.
A typical prior art gravity dump system is shown in U.S. Pat. No. 4,009,906. This patent shows a conventional gravity dump system with two hoppers with a centrally located discharge door.
Another typical door construction is shown in U.S. Pat. No. 3,938,861, wherein the door consists of a rack and pinion system for moving the door for discharging cargo. Similar system is shown in U.S. Pat. No. 4,475,672.
A gravity feed hopper system that utilizes an auger to commute materials before discharge is shown in U.S. Pat. No. 5,395,058. This device crushes large aggregate materials so that they may flow more freely from the hopper.
U.S. Pat. No. 4,617,868 shows a rail car that utilizes multiple hoppers with multiple doors. An interesting "sanitary" plate is shown which protects the hopper door opening from contamination.
A conventional hopper bottom trailer is shown in U.S. Pat. No. Re. 35,580. The trailer shown therein has hopper doors that gravitationally dispense the bulk materials therefrom. Another patent of general interest is U.S. Pat. No. 5,224,761, wherein another trailer with a gravitational system of general relevance is shown.
However, the known prior art fails to advantageously combine the desirable attributes of an auger system with the gravitational discharge system to achieve the desirable attributes of both systems. A few enterprising individuals have discovered that these systems can be combined sometimes. For example, when a pivoting auger forms a portion of the auger system, an operator can often leave the pivoting auger uncoupled so that the cargo is dumped at the coupling juncture, normally at the rear of the tender trailer. Unfortunately, this is not always a practical solution and fails to provide the speed of gravitational systems while suffering from the disadvantage of the auger system.
The known prior art fails to provide an efficient discharge system for unloading bulk material tenders. Known prior art auger systems suffer from problems associated with efficient and practical conversion between the stowed and discharge positions while avoiding unnecessarily structurally instable pivotal couplings. Known multiple segmented or articulated pivoting auger systems are usually difficult and time consuming to convert between stowed and discharge positions. Further, known prior art devices with auger systems that pivot in multiple axes during conversion between stowed and discharge positions often require experienced operators to properly position the auger system. Prior art devices using couplings having terminal hinges or cylinders are inherently instable because the entire weight of the auger is pivoted about a terminus. In particular, no known prior art device distributes the stresses generated during the conversion of the auger system between its stowed and discharge positions adequately.
Thus, a desirable improvement to the art would be an auger system for a tender that enabled an unskilled operator to quickly and efficiently convert the system between a stowed and a discharge position. A particularly desirable improvement would be an auger system that adequately distributed stresses generated during auger conversion.